So, where's the "return" window for asphalt interstate highways? Just direct us, please, and we have, oh, a few miles or so we'd like to turn in for a refund. Exchange? Well, maybe if you have something in a go-with-everything concrete, off the shoulder and with a 30-year warranty.

The News & Observer's Bruce Siceloff reports that part of North Carolina's newest interstate highway -- I-795 between Wilson and Goldsboro -- is cracking. Adding another 3 inches of asphalt to the highway, 23 miles worth, two lanes both ways, which now includes potholes and cracks, would cost about $7 million. But that's chickenfeed for the state Department of Transportation. Thanks to a goofed-up paving job on I-40 in Durham County, a $22.4 million repair was needed last year.

Siceloff reported that there are still questions about what exactly caused the cracking on I-795, which it's safe to say most North Carolinians didn't know existed, at least as I-795. But there's speculation that heavy truck travel on the road may be one culprit.

Consider that last summer, when the highway was still designated as U.S. 117, dozens of trucks were given tickets by the State Highway Patrol because they were hauling 53-foot-long trailers, longer than the 48-foot limit for that highway. But when the freeway was redesignated as an interstate, 53-foot trailers became legal. There might have been a problem, one DOT official said, if trucks were carrying more than the legal weight limit of 80,000 pounds. Cars don't do that much damage to roadways, but overweight trucks do.

It's good to see, however, that the Patrol is apparently cracking down on overweight trucks. Many of us have seen signs on the back of trucks citing the amount in taxes the vehicle pays every year. But the problem with this highway is a good example of why there need be no tears shed for the trucking companies that pay those taxes. Trucks do the damage; they ought to have to pay the freight of repair, so to speak.

State officials say the road was designed to meet specifications applying to interstate highways, but the pavement seems to have been intended for relatively light duty. Was there a lack of planning or foresight here? Are there unintended loopholes in specifications that need to be addressed? How exactly did the switch from U.S. highway to interstate happen, and why? Will the fix of adding more asphalt be a long-term solution to the problem? Does the process of reviewing and approving these projects need fine-tuning?

Now that the road is in place, there is of course no choice but to fix it. It's already carrying increasing traffic, and that presumably will be the case in the future. Nevertheless, an investigation into how this costly situation came about is called for. And let's hope the Highway Patrol keeps up its stringent oversight of trucking in this part of the state, and throughout North Carolina.